[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 151114
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST THU JAN 15 2015

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE
IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL
ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1115 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH CROSSES THE COAST OF SIERRA LEONE NEAR 08N13W
AND CONTINUES SW TO 04N20W WHERE IT TRANSITIONS TO THE ITCZ. THE
ITCZ REACHES FROM 04N20W TO 02N40W...THEN TO THE AMAZON RIVER
DELTA NEAR 00N50W. SCATTERED MODERATE CONVECTION IS NOTED FROM
01N TO 04N BETWEEN 15W AND 25W.

...DISCUSSION...

GULF OF MEXICO...

A CUTOFF UPPER LOW PREVIOUSLY OVER THE FOUR CORNERS AREA IN THE
SW UNITED STATES HAS OPENED INTO A TROUGH AND IS SHIFTING
EASTWARD INTO THE SOUTHERN PLAINS THIS MORNING. THIS WILL
PROVIDE REINFORCEMENT TO A STALLED AND WEAK FRONTAL BOUNDARY
EXTENDING FROM THE STRAITS OF FLORIDA TO 27N90W TO LOW PRES 1016
MB NEAR 24N94W...THEN SOUTHWARD TO 18N94W. COPIOUS MID AND HIGH
LEVEL CLOUDINESS CONTINUES TO MOVE FROM THE EASTERN PACIFIC
ACROSS MEXICO AND INTO THE GULF OF MEXICO N OF 22N.
FOG...DRIZZLE AND LOW CEILINGS ARE NOTED ALONG THE TEXAS AND
MEXICAN COASTLINES WITH 2 TO 4 NM IN FOG OBSERVED AT OFFSHORE
PLATFORMS IN THE NW GULF. COASTAL RADARS CONTINUE TO DISPLAY A
BROAD AREA OF RAIN ALONG THE COASTS OF LOUISIANA AND MISSISSIPPI
AHEAD OF THE APPROACHING UPPER TROUGH...SPREADING EASTWARD INTO
ALABAMA. BUOYS AND PLATFORMS OVER THE NW GULF ARE SHOWING
NORTHERLY WINDS INCREASING THIS MORNING AS THE LOW PRES NEAR
24N94W DEEPENS AHEAD OF THE APPROACHING UPPER TROUGH. WINDS ARE
EXPECTED TO INCREASE LATER TODAY ALONG THE MEXICAN COAST AS THE
UPPER TROUGH MOVES INTO THE LOWER MISSISSIPPI VALLEY FOLLOWED BY
BUILDING HIGH PRES AT THE SURFACE OVER THE SOUTHERN PLAINS AND
NORTHERN MEXICO. ELSEWHERE THE WEAK LOW AND THE REINFORCED FRONT
WILL SHIFT EASTWARD ACROSS THE GULF THROUGH TONIGHT AND EARLY
FRIDAY ACCOMPANIED BY FRESH NORTHERLY FLOW AND DRIER AIR OVER
THE NORTHERN GULF.

CARIBBEAN SEA...

AN UPPER LEVEL TROUGH EXTENDING FROM PUERTO RICO TO THE SW
CARIBBEAN IS BECOMING LESS AMPLIFIED AS IT MOVES ACROSS THE
CENTRAL AND EASTERN CARIBBEAN. THE MAIN IMPACT OF THE TROUGH
ALONG WITH A STRONGER IMPULSE FARTHER NORTH IS TO WEAKEN AND
DISPLACE THE SUBTROPICAL RIDGE N OF THE AREA...ALLOWING TRADE
WIND FLOW FROM THE TROPICAL N ATLC WATERS W OF 55W THROUGH THE
CENTRAL CARIBBEAN TO DIMINISH. REMOTE SENSED SCATTEROMETER DATA
AND IN-SITU BUOY OBSERVATIONS INDICATE GENERALLY MODERATE TRADE
WINDS OVERALL WITH FRESH TRADES PERSISTING ALONG MOST OF THE
COASTLINE OF SOUTH AMERICA. GENERALLY LIGHT TO MODERATE NE WINDS
PERSIST OVER THE NW CARIBBEAN...ALTHOUGH SHIP OBSERVATIONS
INDICATE LOCALLY ENHANCED WINDS OFF BELIZE. IN ADDITION...WHILE
NO RECENT OBSERVATIONS ARE AVAILABLE FROM THE CENTRAL COAST OF
COLOMBIA...IT IS LIKELY THAT FRESH TO STRONG TRADE WINDS PERSIST
THROUGH THE OVERNIGHT HOURS. A FEW TRADE WINDS SHOWERS PERSIST
ACROSS THE LEEWARD AND WINDWARD ISLANDS AS NOTED IN REGIONAL
RADAR IMAGERY...BUT THIS HAS DIMINISHED FROM THE LAST COUPLE
OF DAYS AS TRADE WIND CONVERGENCE HAS WEAKENED. LITTLE CHANGE IS
EXPECTED OVER THE NEXT 24 TO 48 HOURS.

...HISPANIOLA...

DEEP LAYER MOISTURE WILL DIMINISH TODAY AS THE MID LEVELS OF THE
ATMOSPHERE BECOME DRIER IN THE WAKE OF AN UPPER LEVEL TROUGH
THAT MOVE ACROSS THE REGION IN THE PAST COUPLE OF DAYS. THE
DRIER AND MORE STABLE AIR IN CONJUNCTION WITH DIMINISHED TRADE
WINDS WILL ALLOW ONLY ISOLATED SHOWERS ON EASTERN EXPOSURES
THROUGH EARLY FRI.

ATLANTIC OCEAN...

A SHORT WAVE TROUGH MOVING OFF THE EASTERN SEABOARD IS
SUPPORTING SHOWERS AND THUNDERSTORMS ALONG AN ASSOCIATED COLD
FRONT REACHING FROM 31N68W TO THE CENTRAL BAHAMAS AND STRAITS OF
FLORIDA. THE SUBTROPICAL RIDGE...ANCHORED BY 1032 MB SURFACE
HIGH PRES NEAR 31N38W...IS SHIFTING EASTWARD AHEAD OF THE DEEP
LAYER TROUGH. VARIOUS ASCAT SATELLITE PASSES OVER THE PAST
SEVERAL HOURS INDICATE FRESH TO STRONG TRADE WINDS PERSISTING S
OF 25N E OF 50W. OVER THE NEXT 24 HOURS...EXPECT FOR THE COLD
FRONT TO CONTINUE MOVING E WHILE WEAKENING AND FOR THE HIGH
PRESSURE OVER THE E ATLANTIC TO DRIFT NE.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
CHRISTENSEN

This weather bulletin was brought to you by:
www.nashvilleweather.net